Rudolf Langhans

This article is based on a document of fellow lamp engineer and collector Edward J. Covington, which appeared on his website of biographical sketches of persons involved in the lamp industry. Following his passing in February 2017 and with kind permission of his family, Ed's words have been preserved and subsequently expanded with new material by this author, to maintain continued access to the research he initiated.

Biography
In the latter part of the 1880s and the early part of the 1890s Rudolf Langhans, of Berlin, Germany, did experimental work on a new filament that involved silicon. Such a lamp is in the William J. Hammer Collection7. The lamp was brought out in England in 1899 under the name of 'Premier filament'. Quoting from an article in Electrical World and Electrical Engineer3:

"The filament consists of carbide of silicon coated with silicon and carbon and is said to be capable of standing a higher temperature than pure carbon..."

From 1891 to 1893 Langhans worked at the Lynn plant of the Thomson-Houston Company on a cellulose filament impregnated with silicon but a successful product did not result before the factory closed operations in August, 1893. He worked under the direct supervision of Elihu Thomson and John E. Randall6.